Edwabd weston



(No Mqdel.)

E. WESTON. VACUUM PUMP.

No. 283,545. Patented Aug. 21, 1883.

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UNITED STATES- PATENT OFFICE- EDIVARD WESTON, OF NEWARK, NE\V JERSEY, ASSIGNOR TO THE UNITED STATES ELECTRIC LIGHTING COMPANY, OF NEIV YORK, N. Y.

VACUUM-PUMP.

SPECIFICATION forming part of Letters Patent No. 283,545, dated August 21, 1883.

Application filed April 6,1883. (No model.) 7 1 and useful Improvements inVacuum-Pumps, of

which the following is a specification, reference being had to the drawings accompanying and forming a part of the same.

My improvements relate to apparatus for producing high vacuums, and more particularly to that class of instrument commonly known as the Geisler pump," the objects be ing mainly to simplify the construction of such apparatus by dispensing with certain parts, and also to increase the efficiency of the same by combining with the exhaust apparatus proper a vaeuum-chamber of improved constructioninto which the residual air is delivered in the operation of exhausting.

My improvements are illustrated in the accompanyin g drawings, which represent, in 'Figure 1, a complete pump in elevation, in Fig. 2, valve mechanism in vertical section, and in Fig. 3, a modified form of valve, alsoiu section.

Similar letters indicate corrcspoiuling parts in the several figures.

D is the usual vacuum chamber or balloon, from which extends downward a glass tube, A, thirty inches or more in length. A rubber or flexible tube, B, connects the lower end of tube A with a movable mercury-receiver, O. The upper portion of chamber Dtapers off at E into a tube, e, which is first extended hori- .zontally, then bentinto an elbow, and then joined to a globe, I at a point slightly above the lowest part of the globe. From globe F leads a tube, G, containing a stop-cock, g, and connected or adapted for connection with any common exhaust apparatus, whi eh is not sh own in the drawings, as itof itself forms no part of the present invention.

To the tube A, immediately below theeha-mher D, isjoined a tube, H, which connects with a vertical tube, K, to the lower end of. which is applied a flask, M, for containing an anhydrous substance. The upper end of tube K is adapted for receiving the lamps or vessels to be exhausted, and a stop-cock, [,is placed in the tube K for shutting off communication between the lamps and the pump. To pre vent the mercury flooding the tube K during the operation of the pump, the tube II may be lengthened, though I prefer to employ a com- 5 5 paratively short tube and an automatic valve, which closes when the mercn ry rises to a given height. For this purpose I employ valves of various kinds, the most practicable forms being those illustrated.

In Figs. 1 and 2 an electromagnetic valve is shown, the construction of which is as follows: The tube H is contracted, as at a, then widened, forming a valve-seat, b, and a chant ber, c. It is then contracted again at t1, and above this point is formed a globe, f, the purpose of the globe being to retain any mercury that may leak through the valve until the valve opens, when it falls back into the tube A. The chamber 0 contains a valve, N, composed partly or wholly of iron. It is held off from its seat by a spring, S, a shoulder or flange, n, being formed in the sides of the chamber 0 to aid in this. Around the chamber 0 is placed a helix, 1?, of insulated wire in such position that when traversed by a current it will draw the valve N down upon its seat. The circuit of the helix is to be made and the valve closed whenever themercury-receptacl e C is elevated, so that a convenient means of effecting this So is to employ a stand, '1, for the receptacle, provided with a hinged rest which is raised normally from the lower platform, 1, by a spring, A contact-piece, r, and an arm, 1-, in its path of movement are connected with 8 5 the terminals of the circuit from a suitable battery, and close said circuit when the receptacle C is lifted off the stand, and permits the spring 8 to raise the rest t. In lieu of this form of valve an ord-inaryfloat-valve, N, may be used. hen, in this case, the mercury rises in the chamber 0, in which the valve N is contained, the latter, being buoyant, is forced up against its seat a, and prevents the flow of mercury'into the chamber f or tube K.

In operating the apparatus which I have now described the air is first withdrawn as far as possible from the pump and lamps, or

other devices connected therewith, by means of a -mechanical pump connected with tube G. The receptacle 0 is then raised until the mercury has filled the chamber D and a small quantity run over tube einto the globe F, carrying with it the residual air from the chamber D. After this operation has been repeated a number of times a very high degree of Vacuity will be found to exist in the pump. The exhaustion of the globe F is maintained by the mechanical pump, coinmunicationbetween the globe F and the chamber D being closed by the mercury, which, owing to the slight difference in the degree of exhaustion in the globe F and chamber D, remains in the elbow of tube 6.

The construction of the apparatus whichhas thus been specifically described may obviously be varied to some extent without departure from the invention. The form shown is, however, the most practicable of which I am aware, and overcomes many of the difficulties usually encountered in apparatus of this kind, particularly the difficulty of delivering or expelling into the exhaust-chamber the bubble of residual air from the chamber D. This construction also dispenses with the stop-cock, which is usually placed near the top of the chamber D. I

I would state that the valve mechanism herein shown and described is not specifically V claimed as I have made it the subject of a separate application for Letters Patent; but

What I claim is 1. The combination, with the vacuum-cham- 3 5 ber of an air-pump constructed substantially as described, of an exhaustchamber and a tube containing an elbow or trap, and connecting the exhaust-chamber with the upper portion of the vacuum-chamber, as set forth.

2. The combination, with the vacuum-chamber of an air-pump of the kind described, of an exhaust globe or chamber and a tube connecting the upper portion of the vacuunr chamber with the lower part of the exhaustchamber, the said tube being extended from the vacuum-chamber for a short distance horizontally and then bent into an elbow or trap, as and for the purpose set forth.

3. The combination, in a vacuum apparatus of the kind described, of a Vacuum-chamber, as D, and an exhaust globe or chamber, as F, connected therewith in substantially the manner set forth, with tube A, tube H, a valve contained therein, and tube K.

In testimony whereof I have hereunto set my handthis 2d day of April, 1883.

EDWARD \VESTON.

I Witnesses:

LEONARD E. CURTIS, W. H. HARTLEY. 

